Select text object by name and change font via script
Example below is based on windows file location.

import bpy

my_name = 'ALGER.TTF'  #name of text object
new_font = 'G:\\Blender Working folders\\Fonts\\ALGER.TTF'  #file location of new font
for ob in bpy.data.objects:
    if ob.name == my_name:
        ob.data.font = bpy.data.fonts.load(new_font)